Climbing Perch

Adults reach up to 20 cm in length, with some specimens growing to 25–30 cm. Females are typically noted to be slightly larger than males. The fish's coloration varies from gray to brown, with barely discernible dark speckles and two black spots located at the base of the tail and behind the gill cover. Their fins are rounded and significantly shifted towards the caudal part of the body.

These fish are widely distributed in Southeast Asia and have also been introduced to Australia and the Pacific Islands. They are found in almost all aquatic biotopes: from swamps and lakes to river backwaters, canals, and even in rice paddies or temporary forest puddles. During the rainy season, when coastal areas are flooded, Anabas can move significant distances from the main channel. However, when the water recedes, the fish often find themselves in isolated water bodies. In such cases, to survive, they are capable of long overland migrations, sometimes covering hundreds of meters in search of a new habitat. Movement is achieved using pectoral fins and lateral movements of the tail and posterior part of the body. Such "journeys" do not occur regularly, but only when the water body completely dries up. In extreme conditions, Anabas can enter a state of dormancy for several weeks, burying itself in the substrate.

These fish are not suitable for keeping in a community tank due to their large size in adulthood and predatory nature. Any small fish in their vicinity will be eaten. Coexistence is only possible with species of similar size, for example, with Pacu, and only in a very spacious aquarium. There is no precise data on intraspecific aggression in Anabas, which is explained by their great diversity and wide habitat range. In different regions, representatives of this species can exhibit both friendly behavior towards conspecifics and extremely aggressive attacks on potential rivals. It has been noted that an increase in water temperature can provoke more aggressive behavior even in normally calm Anabas.

For keeping a single Climbing Perch, an aquarium of at least 200 liters is required. Anabas can adapt to various conditions, so the aquarium setup primarily depends on the aquarist's preferences. It is only important to follow a few recommendations: provide shelters, a soft substrate, and areas with dense vegetation. The fish is undemanding regarding water hydrochemistry and temperature. However, attention should be paid to the lighting level and internal current: the equipment must be configured to provide subdued light and, if possible, minimize water movement. Aquarium maintenance includes regular cleaning of the substrate from organic waste and weekly partial water changes (10–15% of the total volume) with fresh water.

The diet of Anabas consists of small fish, invertebrates, and mollusks, as it leads a predatory lifestyle. In a home aquarium, these fish readily accept large live and frozen foods. Many aquarists successfully acclimate them to granulated dry foods, which are protein-based with added plant components. Before purchasing the fish, it is crucial to clarify its current diet.

Anabas is one of the few labyrinth fish that shows no parental care for its offspring. During the breeding season, males develop a reddish tint on their ventral fins and tail, and their dark speckles become more distinct. Females become noticeably rounded at this time. After brief courtship rituals, spawning begins, accompanied by peculiar "embraces" between the partners. At the climax, hundreds of eggs and milt are released. The total number of eggs in one spawning can reach several thousand. The eggs float freely on the water surface. Fry hatch within 24 hours, measuring 2–3 mm in length. Breeding Anabas in home aquariums is practically impossible without the use of hormonal injections, which are widely used in commercial aquaculture on fish farms.

The main cause of most diseases in Leaf Fish is unsuitable keeping conditions and poor-quality nutrition. If initial symptoms are observed, it is first necessary to check water parameters and the concentration of dangerous substances such as ammonia, nitrites, and nitrates. If the indicators deviate from the norm, they should be brought back into order, and only then should treatment begin. More detailed information on symptoms and treatment methods can be found in the "Aquarium Fish Diseases" section.

When purchasing an Anabas, it is advisable to choose young specimens, as adult fish adapt less well to new conditions and may exhibit pronounced intraspecific aggression. Carefully inspect the fish for skin and fin damage, which often occurs during improper transport or housing. A healthy Anabas should have clear, unclouded eyes, and its breathing should be regular. Avoid specimens that appear emaciated or show signs of lethargy, unless this is related to the species' nocturnal activity.

Be aware that Anabas have sharp spines on their gill covers, which can easily damage a net or your hands. In the store, it's best to observe the fish's behavior in the aquarium: a healthy Anabas is curious and may be timid. It's important to ask the seller what type of food the specific specimen is accustomed to, as transitioning to dry pellets after a live diet may take time. Do not purchase fish if there are signs of infectious diseases among other inhabitants in the store's community tank.